Ask the Dentist – What are Canker Sores/Aphthous Ulcers?

by Dr Nicole Andersen

What are canker sores?
Canker sores, also known as Aphthous Ulcers, are a common oral lesion that occurs in more
than half of the population. They occur on the soft tissue inside the mouth and appear as small round or oval white or yellow sores. They can show up as a single ulcer or as multiple sores at any given time.

What causes canker sores?
There are several possible causes, but no one knows the exact cause for certain. These
possibilities include an immune system malfunction, that causes white blood cells to
temporarily attack the cells lining the inside of the mouth. Other causes may be linked to
nutritional deficiencies, a reaction to a food or component of toothpastes or mouthwashes, or an association to a systemic condition including Crohn’s disease.

Can you prevent canker sores?
There is no medication or product to help prevent canker sores. At this time, the best way to
help prevent canker sores is to track connections between canker sore outbreaks and food, or products that you may be using at that time. There are some toothpastes that do not use the detergent SLS (sodium lauryl sulfate) that can help some patients reduce the frequency of outbreaks.

How long do canker sores last?
Canker sores are self limiting and will go away without treatment in one to two weeks. There
are over the counter products that claim to help with the soreness until the ulcer heals. Different products may work better or worse for any one patient.